Mysterious Power Surges Damage BART Rail System

SAN FRANCISCO (AP) - Bay Area commuters are dealing with overcrowded trains, travel delays and other inconveniences for the second time in two weeks due to a mysterious electrical problem affecting the region's rail transit system.

Bay Area Rapid Transit officials said 50 of their train cars - twice as many as originally estimated - were damaged by unexplained power surges on Wednesday.

Two weeks ago, another 80 BART cars also were taken out by voltage spikes, but in a different segment of the system.

Spokeswoman Alicia Trost says BART employees haven't been able to determine what's causing the problem and outside experts are being flown in to evaluate.

The short section of track 36 miles west of downtown San Francisco where the latest surges happened remained shut down on Thursday so more train cars wouldn't be damaged.

Copyright 2016 The Associated Press.